Daniel,

Great writeup. I looked as you did and can not find any reference to a maintenance schedule for the pump filter.

The WIS says.............

When I pulled my pump down to change out the valve block, I changed my filter but did not find it clogged as yours was. I replaced mine at 105K miles.

Bob

 

........I was horrified when I removed this filter and saw its condition. It was clogged with debris in both ends, and the filter element inside was hard and loose. It makes a clunking sound when you shake it. It has an awful burnt scent. When I tried to blow it from both sides, I discovered that the movement of the loose filter could block the flow of air......l

What was first - chicken or egg?

The burnt scent may be a result of the burned motor and the smoke which comes with that fault. Incoming (smoke) and outgoing air goes through the filter (part a in the picture).

 

Thank you very much for your comments, Bob and Bullethead. I value your contributions as very important.

Bob's finding that his filter was not clogged could be reassuring to many owners. He mentions that he changed his valve block. I assume that his pump wasn't seized or burned as in my case.

The diagram which Bullethead attached and his observation that incoming and outgoing air goes through the filter confirms the explanation of Valotus. When one looks at the pictures of both ends of the clogged filter, the difference in colour confirms his conclusion that the burnt scent may be a result of the burned motor and the smoke which came as a consequence of it. The one end of my filter is black (obviously caused by smoke coming from the pump) (Edit: I was wrong. Please read on).The other end is brown (Edit: I discovered it was the rusted bottom side of the filter element after I had dissected the filter).

It seems that the filter should indeed be replaced after the motor burned or seized.

Daniel

 

Is it possible that broken hose between compressor and filter cause failure of airmatic compressor?

 

It will cause failure sooner or later. At least piston ring and cylinder will be scratched so that compressor can't rise pressure anymore.

Original flexible rubber hose between filter and compressor intake seems often to be cracked and faulty. And if it goes broken, it's like you don't have filter at all.

Air intake filter is there for only one reason; to prevent any dirt particles ending up into system. For same reason are oil filters, fuel filter, engine air intake filter, etc. All of these filters are meant to be replaced (or cleaned in some cases) after certain time, so why would this be an exception.

The original airmatic filter is Mann WK 32/6, which is a common paper element fuel/air filter. It costs couple of dollars or euros, even if bought from MB dealer.

 

I am not a technician. My response is therefore based on reasoning and not on experience.

The compressor is located very close to the front of the vehicle, behind the air inlet grate of the lower bumper section. A broken hose would expose the compressor unfiltered air, debris and the elements. It could damage the compressor as well as the valves and cause failure.

I would welcome the input from more experienced members as I regard this as a very relevant question. MB changed the design of the intake line. With the new pump, the line fitting is now on the opposite side (closer to the electrical connections). That means the original rubber hose which connects the filter to the pump line is too short. A member of the forum advised that one should buy a longer rubber hose which is a lot cheaper than buying the previous problematic intake line (it seems that it was more prone to leaks). The obvious choice would be to use a fuel hose which I would not recommend (It has a thicker wall than the original hose and is therefore not as flexible. The vibration of the pump could therefore cause more friction on the rubber housing of the filter, damage the grommet and cause the filter to pop out of its mount point). Or one could opt for an inferior hose that could shave through if it is not fitted properly.

I would recommend a good quality hose with a 2mm wall that is able to withstand the wind and the elements. Friction against the right front engine compartment panelling and other parts should be eliminated.

Daniel

 

The anatomy of the airmatic filter

A broken hose exposes the compressor as well as the other parts of the airmatic system to dirt particles. It will cause failure sooner or later, as Valetus pointed out. it's like you don't have filter at all.

A loose filter element could also expose the system to dirt particles. When dissecting my old airmatic filter, I discovered that it had been inoperative because the filter element had become loose of the small plastic tube on which it is mounted. This caused the clunking noise (I mentioned this in a previous post) when I shook it.

One of the attached pictures show the top half of the plastic housing with a small tube. The intake of the filter element is mounted on this tube (it literally hangs on it). When I pressed it back on its mounting, I had to use force to get it loose again. It remains a mystery how it became loose inside the plastic housing. Could this be a design flaw? The consequence: the air which entered the filter bypassed the filter element.

I also discovered that some of my previous findings were wrong. The filter wasn't clogged with debris. The brown "debris" which I saw at the one end was actually the rust on the closed end of the filter. The "black" colour on the other side was also not "debris" that was caused my smoke as I assumed. It was the open or intake end of the filter which seemed black because it led to the inside of the filter. One photo shows that the inside of the filter has the same colour as the outside. I therefore have to offer my sincere apologies: my conclusions before I dissected the filter were completely wrong!

However, the results of the dissection has turned out to be more alarming. The filter element had become loose of its mounting inside the plastic housing, which meant that the intake air bypassed the filter element. My compressor had therefore been exposed to dust particles which entered the aft. Although this location is more sheltered that a broken hose, we all know that dust finds it way...

Daniel

 

Any tell tales?

A broken hose exposes the compressor as well as the other parts of the airmatic system to dirt particles. It will cause failure sooner or later, as Valetus pointed out. it's like you don't have filter at all.

A loose filter element could also expose the system to dirt particles. When dissecting my old airmatic filter, I discovered that it had been inoperative because the filter element had become loose of the small plastic tube on which it is mounted. This caused the clunking noise (I mentioned this in a previous post) when I shook it.

One of the attached pictures show the top half of the plastic housing with a small tube. The intake of the filter element is mounted on this tube (it literally hangs on it). When I pressed it back on its mounting, I had to use force to get it loose again. It remains a mystery how it became loose inside the plastic housing. Could this be a design flaw? The consequence: the air which entered the filter bypassed the filter element.

I also discovered that some of my previous findings were wrong. The filter wasn't clogged with debris. The brown "debris" which I saw at the one end was actually the rust on the closed end of the filter. The "black" colour on the other side was also not "debris" that was caused my smoke as I assumed. It was the open or intake end of the filter which seemed black because it led to the inside of the filter. One photo shows that the inside of the filter has the same colour as the outside. I therefore have to offer my sincere apologies: my conclusions before I dissected the filter were completely wrong!

However, the results of the dissection has turned out to be more alarming. The filter element had become loose of its mounting inside the plastic housing, which meant that the intake air bypassed the filter element. My compressor had therefore been exposed to dust particles which entered the aft. Although this location is more sheltered that a broken hose, we all know that dust finds it way...

Daniel

Daniel, I appreciate your resolve in tracking this FAIL. Question, before you dissected the filter housing, did the filter rattle inside the housing?

The appearance might indicate that the filter had processed little air given the age of the part.

As it was loose, perhaps the filter was shocked loose at some time early in its life by a front end collision? The simple compression fitting in the design could lend its self to shock or even temperature differential allowing the filter to sweat loose. What's your best guess?

 

I've been repairing my defective compressors lately and living in the rust belt I find the inside of the compressor crank region to be lightly coated in salt residue. The filter works great on solids, but stinks when it comes to dissolved solids. Any suggestions on how to stop the salt water from going right through the paper filter?

 

I would suggest that one should find the entry point of water.

The hose of the pump draws air from above the mount point of the filter (it fits into a rubber grommet (part number 2203280279) that is mounted upside down on the frame aft underneath the wiper fluid and coolant reservoirs). This area is well protected from the elements. It is unlikely that water could enter from there unless the grommet is punctured or water from a leaking reservoir is dripping from the upper part of the frame aft into the intake tube. I have not inspected the mounting area of the grommet, but I assume that the engineers would have considered preventative measures in this regard.

Water could also enter through a broken or leaking hose. The compressor is located right behind the air inlet grate of the lower bumper section and is therefore exposed to rain and snow.

I noticed that you had read the thread of Valotus regarding the water content in the the desiccant of the compressor. When he opened his 2004 compressor, he discovered the dryer unit was soaking wet. You mentioned in that thread that you have been doing a lot of reading about the various desiccants (You know much more about compressors than me!). I assume therefore that the salt residue is something completely different, also because you refer to the crank region of the compressor.

If the preventative measures of the engineers fail to prevent water from entering the filter in your region, I would suggest designing and installing a drip tray. It could save you a lot of trouble and money.

Daniel

 

Asureyes, Thank you for responding.

It did rattle before I dissected it as reported in #1 and in the previous thread "Symptoms of a seized airmatic pump".

The attached picture shows some dirt particles against the inside wall of the lower section of the plastic housing. It indicates that contaminated air bypassed the filter. Also visible in the picture are the extending ribs at the bottom on which the filter element rested after it had become loose. I think it was designed this way to prevent blockage if the filter element might become loose.

The previous owner assured me that the car had not been damaged in an accident. However, I do remember that the workshop manager asked me if it had been involved in an accident because the front parts seemed to be new (the car is still in an excellent condition). I would not exclude some kind of shock because the workshop manager also pointed that the splash guards of the wheel hubs were damaged (picture). It seems that the car might have hit the ground with the front wheels removed (perhaps an accident in the workshop?).

I am in no position to speculate over temperature differential allowing the filter to sweat loose. My gut feeling rules it out because that should not happen with a Mercedes Benz part. I think the engineers did consider that metal and plastic expand and contract differently when the temperature changes rapidly. Maybe they allowed too much room for the filter element to expand.

Daniel

 

My old filter had inner parts loose too. It was from -04 E270 and never changed as far as I know.

I guess MB (or Wabco as manufacturer) had chosen this filter model just for its dimensions and inlet/outlet diameters. That's because arrow on the side of filter shows direction of flow as it was originally designed. In this case, when filter is correctly installed, it's upside down and arrow shows towards the air flow.

However, it may not be a big deal with air volumes of this system.

 

According to the WIS (AR32.22-P-2001I), "the arrow on the air filter (2) must point towards the longitudinal member", which refers to the rubber grommet (see the illustration).

I bought a VW fuel filter and decided to dissect it as well. It is a FRAM G4705. The MB airmatic filter is six times (600%) more expensive than the FRAM filter. I compared all the dimensions and came to the conclusion that they are almost identical.
a. Both filters use the same filter element.
b. The inner construction is identical.
c. The outer dimensions of the plastic housing are identical.

The only differences as far as I can see are
d. the MB airmatic filter has a lip on its outer housing where the rubber grommet is fitted.
e. The tube of the airmatic filter to which the arrow points has an external diameter of 8mm and the fuel filter 10mm.

The pictures are attached.

Daniel

 

My conclusion

I have waited for someone else to draw a conclusion, but it seems that I have to do it. I do not think that part number 220 320 00 69 was designed for the airmatic suspension system. It seems to be a fuel filter that is being used the wrong way around. That is why it becomes loose. If one should consider to use it in accordance to the direction of flow as it was originally designed, then it would not fit in its mounting place. It would also expose the metal part of the filter element to the elements which could cause rapid corrosion, especially in the salt belt.

I shall communicate my conclusion to MB in Germany, and suggest that they should consider to design a new air filter for the airmatic suspension system. It simply does not make sense to risk exposing very expensive equipment to the elements by using a filter that was not originally designed for its function in the system (BTW the VW version sells for $2 in South Africa).

Daniel

 

Update of my letter to Daimler AG in Germany

I shall communicate my conclusion to MB in Germany, and suggest that they should consider to design a new air filter for the airmatic suspension system. It simply does not make sense to risk exposing very expensive equipment to the elements by using a filter that was not originally designed for its function in the system.

I addressed my letter to Mr. Jochen Haab, the Manager of Technical Support of Daimler AG in Germany. I sent it on 27-03-2017. The letter is attached.

Daimler AG responded on 07-04-2014 informing me that Mr. Jochen Haab isn`t the responsible person for my request. They forwarded his response to me (I can read German) and requested: "Please tell us the name of another Person." Could Bullethead or any other member help, please?

Daimler AG also forwarded my letter to Mercedes-Benz South Africa. They kindly asked me to bear with them until such time they have more accurate information pertaining to my enquiry.

I am glad to report that my letter has been received in a good spirit.

Daniel

 

..... Could Bullethead or any other member help, please?....

I don't know a special responsible person. In case someone send a letter to Stuttgart MB will forward it to their customer assistance center in NL-Maastricht.

DaimlerChrysler Customer Assistance Center N.V.
P.O. Box 1456
NL-6229 EN Maastricht

This center has been established for european customers.

 

Thank you, Bullethead. That is also what Jochen Haab suggested to dialog@daimler.com:

Ich möchte Sie bitten, diese Anfrage entweder an den Fachbereich Achsen / Federung (RD/FC) oder aber an einen Kollegen im Bereich GSP/TPC bzw. das CAC in Maastricht offiziell zur Bearbeitung weiter zu leiten (bitte mit dem Vermerk, dass ich nicht zuständig bin).

Daniel

 

Mercedes-Benz South Africa has kindly replied to my suggestion. The letter is attached.

Daniel

 

Recently I met an old man on the street who has pre-facelift W220. We chatted and I asked whether he had any airmatic issues. He said that he repairs his car himself and every winter he changes Airmatic air filter which is full of salt (in this country salt is used on roads in winter).

While the guy has not read this thread, the folk-culture at least in salty countries rule that airmatic air filter _is_ serviceable part. As well as changing fuel filter before and after every winter.

 

By "serviceable item" MB may mean the internal parts of the filter cannot be replaced - the whole plastic unit must be.

 

I am replacing mine as part of my cars winterizing. I replaced both front struts and relay a year ago Aug, but never touched the filter.
My feelings are filters are meant to be changed. You change your engine air, oil, fuel filters and cabin filters so why not a $10 air compressor filter. If I would have found out earlier about the compressor filters I would have changed mine spring and fall.
Everyone says it is really easy and here they are $18 so why not?
My AIRMATIC is working 100% knock on wood and would like to keep it that way. So while I have the wheels off to install the winter wheels and tires why not spend 15-20 minutes replacing it. I am also replacing my front brakes( no warnings lights, squeaks or pulsing) just figure it is a cheap and quick piece of mind. I am also replacing my sway bar links ends. I replaced the sway bar ball joints and noticed that the link ends were pretty much on their way out. So if I am getting dirty anyway might as well change the AIRMATIC filter.
I figure if the brakes are replaced now they will go out in the middle of the winter when everything is covered in salt, slush etc.

 

Your car has break wear indicators specifically so you do not need to prematurely change the brakes

If it gives you peace of mind go for it, but I don't like to replace parts that are still serviceable

 

I realize they have wear indicators.
I have had the car almost 2 years and have not had any with the brakes. The brakes passed the safety standards when I registered in Jan 2012 and 22,000 kilometres ago.
I do have a bit of a lead foot and drive in a lot of stop and go traffic.
I am one of those guys that since I am lifting the car to replace the all season and am digging everything out might as well do the brakes.
Crappy weather long drive at the holidays rather do them before then have the light come on when I have no time.
Also my sway bar links need to be replaced(they are not completely shot still have so life left)
So if I am going to get dirty might as well do the brakes then I know I am good for awhile.
Like you say just piece of mind. I also find waiting till the sensor tell can cause other issues.
I have never had any caliper issues(stuck, piston pitted etc) as I change my pads sooner then later.
This time I will skip rotors and next time I will replace both. I measured them a few months back and they are well within limits and no grooves. Will have them turned just clean the surface up.

 

I always change the compressor with new struts. With a new compressor, always a new relay and filter.

 

Hi
I am tackling replacing my AIRMATIC filter this weekend. How bad is it to get to? Where is it exactly. I have looked in the stickies they cover everything but replacing the filter.

 

Filter is right above the compressor, you will see the line that connects to the filter, which in turn plugs right into the frame rail. Pretty easy job to do.

 

I have an E500 that we are servicing prior to sale. On that particular model, Airmatic is standard. I'm replacing all of the pump bushings (my cost at dealer wholesale is $7.20 for all three) and also the filter (my cost is $13.50).

It is a very easy service item.

 

Quick question on the orientation of the filter. Should the arrow point towards or away from the compressor?

 

MrHawksley,

You probably have this all figured out by now, but the arrow on the filter must point AWAY from the compressor. As has been mentioned previously, this is probably a repurposed fuel filter being used in this application (to filter dust), and so the arrow direction, though technically "wrong" probably doesn't affect the end result at all.

However, how hard could it have been for MB to design the rubber hoses and filter holder so that the arrow on the filter would point in the right direction? It would have saved many of us (myself included) some head-scratching.

-SBH

 

This is a older thread, but a thread with some very pertinent information on replacement of the airmatic pump filter.

I changed a filter yesterday, and it can make a simple job a very tough job, as the filter, in my situation, became lodged to the filter housing (called a grommet). It took about one hour to separate the filter from the rubber grommet housing, using pb blaster. Others have had the housing fail when trying to remove it- so make sure you have a replacement housing on hand. I used dieltric grease on the inside of the housing prior to insertion of the replacement filter to support future removal.

I suggest one has the following additional parts on hand when replacing the airmatic filter:

2203280279 grommet/ housing for the filter (about $6 USD)
2203270182 hose from filter to air pump
220320 00 69 air filter (Mann Part # wk 32/6

I think this is a critical maintenance item, but if your w220 never had this filter change and you live in a high humidity or a cold climate, changing the filter may be a little more work than it seems as the filter may have become one with the grommet housing over time.

And above all, there is a very good change the hose from the filter to the pump has a large, hard to see tear which means the air pump is getting unfiltered and and likely water drawn into it.

For under $25 in parts, once can maintain the parts that protect the air going to the pump, which may be the reasons pumps fail.